<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>快速入门</title>
    <script src="./js/jquery-3.3.1.min.js"></script>
</head>
<body>
<div id="title">标题</div>
<div id="body">内容</div>

<script>
    var title = $("#title");
    var body = $("#body");

    document.write(title.html());<br/>
    document.write(body.html());
</script>

</body>
</html>